Genetics is the study of genes and heredity and the differences in organisms that arise from their genes. The genetic traits passed on to us from our parents determine how we look, influence what diseases we have, and may also affect our behavior. By studying genes and how they are inherited, researchers can understand many diseases and learn how to treat and possibly prevent them. In this activity, you will discover the history of the science of genetics and learn simple tools that will help you understand how genes are passed on from one generation to the next.